ansible/test/integration/targets/lookup_unvault/unvault.yml

- name: test vault lookup plugin
  hosts: localhost
  gather_facts: false
  tasks:
    - debug: msg={{lookup('unvault', 'foot.txt.vault')}}
    - name: verify vault lookup works with both vaulted and unvaulted
      assert:
        that:
            - lookup('unvault', 'foot.txt.vault') == lookup('unvault', 'foot.txt')